Displaying publications 61 - 80 of 350 in total

Abstract:
Sort:
  1. Chan KW, Khong NM, Iqbal S, Umar IM, Ismail M
    Int J Mol Sci, 2012;13(7):8987-97.
    PMID: 22942747 DOI: 10.3390/ijms13078987
    Sweet potato is known to be rich in healthful antioxidants, but the stability of its antioxidant properties under gastrointestinal pH is very much unknown. Hence, this study aimed to evaluate the changes in antioxidant properties (total contents of phenolics and flavonoids as well as antioxidant activity) of sweet potato flour (SPF) under simulated gastrointestinal pH conditions. It was found that the yield of SPF crude phenolic extract increased from 0.29 to 3.22 g/100 g SPF upon subjection to gastrointestinal pH conditions (p < 0.05). Also elevated significantly were the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity of SPF (p < 0.05). In summary, the antioxidant properties of SPF were enhanced under gastrointestinal pH conditions, suggesting that SPF might possess a considerable amount of bound phenolic and other antioxidative compounds. The antioxidant properties of SPF are largely influenced by pH and thus might be enhanced during the in vivo digestive process.
    Matched MeSH terms: Antioxidants/chemistry*
  2. Thoo YY, Abas F, Lai OM, Ho CW, Yin J, Hedegaard RV, et al.
    Food Chem, 2013 Jun 1;138(2-3):1215-9.
    PMID: 23411234 DOI: 10.1016/j.foodchem.2012.11.013
    The synergistic antioxidant effects of ethanolic extracts of Centella asiatica (CE), and α-tocopherol have been studied. The types of interactions exhibited by CE and α-tocopherol combined at different ratios were measured using three assays: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical-scavenging capacity, the β-carotene bleaching system and liposome peroxidation assays. Fixed-fraction isobolographic analysis was used to detect any inducement of the antioxidant activity compared with the individual activities of CE and α-tocopherol. Of all synergistic combinations of CE and α-tocopherol, only fraction 2/3 showed the synergistic combination that fits well in three different assays and can be explained by the regeneration of α-tocopherol by CE despite the interaction effect of β-carotene present in the analytical assay. This phenomenon involved complex interactions between CE and α-tocopherol to exhibit different degrees of interactions that eventually increased antioxidant activity.
    Matched MeSH terms: Antioxidants/chemistry*
  3. Atangwho IJ, Egbung GE, Ahmad M, Yam MF, Asmawi MZ
    Food Chem, 2013 Dec 15;141(4):3428-34.
    PMID: 23993503 DOI: 10.1016/j.foodchem.2013.06.047
    The antioxidant and anti-diabetic properties of the sequential extracts of Vernonia amygdalina based on the chemical composition of the most effective anti-diabetic extract were studied. Using DPPH and ABTS radical scavenging as well as FRAP assays, the extracts showed a consistent dose-dependent trend of potent antioxidant activity in the following solvents: water extract>methanol extract>chloroform extract>and petroleum ether extracts. In the oral glucose tolerance test, the chloroform extract exerted the highest response (33.3%), similar to metformin (27.2%), after 2h compared to the control (50.8%, P<0.05). After a 14-day administration in diabetic rats, the chloroform extract recorded the highest blood (23.5%) and serum (21.4%) glucose-lowering effects (P<0.05). GC-MS analysis of the chloroform extract revealed high levels of linoleic acid (4.72%), α-linolenic acid (10.8%) and phytols (12.0%), as well as other compounds.
    Matched MeSH terms: Antioxidants/chemistry
  4. Alhawarri MB, Dianita R, Razak KNA, Mohamad S, Nogawa T, Wahab HA
    Molecules, 2021 Apr 29;26(9).
    PMID: 33946788 DOI: 10.3390/molecules26092594
    Despite being widely used traditionally as a general tonic, especially in South East Asia, scientific research on Cassia timoriensis, remains scarce. In this study, the aim was to evaluate the in vitro activities for acetylcholinesterase (AChE) inhibitory potential, radical scavenging ability, and the anti-inflammatory properties of different extracts of C. timoriensis flowers using Ellman's assay, a DPPH assay, and an albumin denaturation assay, respectively. With the exception of the acetylcholinesterase activity, to the best of our knowledge, these activities were reported for the first time for C. timoriensis flowers. The phytochemical analysis confirmed the existence of tannins, flavonoids, saponins, terpenoids, and steroids in the C. timoriensis flower extracts. The ethyl acetate extract possessed the highest phenolic and flavonoid contents (527.43 ± 5.83 mg GAE/g DW and 851.83 ± 10.08 mg QE/g DW, respectively) as compared to the other extracts. In addition, the ethyl acetate and methanol extracts exhibited the highest antioxidant (IC50 20.12 ± 0.12 and 34.48 ± 0.07 µg/mL, respectively), anti-inflammatory (92.50 ± 1.38 and 92.22 ± 1.09, respectively), and anti-AChE (IC50 6.91 ± 0.38 and 6.40 ± 0.27 µg/mL, respectively) activities. These results suggest that ethyl acetate and methanol extracts may contain bioactive compounds that can control neurodegenerative disorders, including Alzheimer's disease, through high antioxidant, anti-inflammatory, and anti-AChE activities.
    Matched MeSH terms: Antioxidants/chemistry
  5. El Hachlafi N, Mrabti HN, Al-Mijalli SH, Jeddi M, Abdallah EM, Benkhaira N, et al.
    Molecules, 2023 Aug 06;28(15).
    PMID: 37570883 DOI: 10.3390/molecules28155913
    Cedrus atlantica (Endl.) Manetti ex Carriere is an endemic tree possessing valuable health benefits which has been widely used since time immemorial in international traditional pharmacopoeia. The aim of this exploratory investigation is to determine the volatile compounds of C. atlantica essential oils (CAEOs) and to examine their in vitro antimicrobial, antioxidant, anti-inflammatory, and dermatoprotective properties. In silico simulations, including molecular docking and pharmacokinetics absorption, distribution, metabolism, excretion, and toxicity (ADMET), and drug-likeness prediction were used to reveal the processes underlying in vitro biological properties. Gas chromatography-mass spectrophotometry (GC-MS) was used for the chemical screening of CAEO. The antioxidant activity of CAEO was investigated using four in vitro complementary techniques, including ABTS and DPPH radicals scavenging activity, ferric reductive power, and inhibition of lipid peroxidation (β-carotene test). Lipoxygenase (5-LOX) inhibition and tyrosinase inhibitory assays were used for testing the anti-inflammatory and dermatoprotective properties. GC-MS analysis indicated that the main components of CAEO are β-himachalene (28.99%), α-himachalene (14.43%), and longifolene (12.2%). An in vitro antimicrobial activity of CAEO was examined against eleven strains of Gram-positive bacteria (three strains), Gram-negative bacteria (four strains), and fungi (four strains). The results demonstrated high antibacterial and antifungal activity against ten of them (>15 mm zone of inhibition) using the disc-diffusion assay. The microdilution test showed that the lowest values of MIC and MBC were recorded with the Gram-positive bacteria in particular, which ranged from 0.0625 to 0.25 % v/v for MIC and from 0.5 to 0.125 % v/v for MBC. The MIC and MFC of the fungal strains ranged from 0.5 to 4.0% (MIC) and 0.5 to 8.0% v/v (MFC). According to the MBC/MIC and MFC/MIC ratios, CAEO has bactericidal and fungicidal activity. The results of the in vitro antioxidant assays revealed that CAEO possesses remarkable antioxidant activity. The inhibitory effects on 5-LOX and tyrosinase enzymes was also significant (p < 0.05). ADMET investigation suggests that the main compounds of CAEO possess favorable pharmacokinetic properties. These findings provide scientific validation of the traditional uses of this plant and suggest its potential application as natural drugs.
    Matched MeSH terms: Antioxidants/chemistry
  6. Hashim NM, Rahmani M, Ee GC, Sukari MA, Yahayu M, Amin MA, et al.
    Molecules, 2012;17(5):6071-82.
    PMID: 22614861 DOI: 10.3390/molecules17056071
    One of the most promising plants in biological screening test results of thirteen Artocarpus species was Artocarpus obtusus FM Jarrett and detailed phytochemical investigation of powdered dried bark of the plant has led to the isolation and identification of three xanthones; pyranocycloartobiloxanthone A (1), dihydroartoindonesianin C (2) and pyranocycloartobiloxanthone B (3). These compounds were screened for antioxidant, antimicrobial and tyrosinase inhibitory activities. Pyranocycloartobiloxanthone A (1) exhibited a strong free radical scavenger towards DPPH free radicals with IC50 value of 2 µg/mL with prominent discoloration observed in comparison with standard ascorbic acid, α-tocopherol and quercetin, The compound also exhibited antibacterial activity against methicillin resistant Staphylococcus aureus (ATCC3359) and Bacillus subtilis (clinically isolated) with inhibition zone of 20 and 12 mm, respectively. However the other two xanthones were found to be inactive. For the tyrosinase inhibitory activity, again compound (1) displayed strong activity comparable with the standard kojic acid.
    Matched MeSH terms: Antioxidants/chemistry
  7. Mazlan NA, Mediani A, Abas F, Ahmad S, Shaari K, Khamis S, et al.
    ScientificWorldJournal, 2013;2013:312741.
    PMID: 24319356 DOI: 10.1155/2013/312741
    The methanol extracts of three Macaranga species (M. denticulata, M. pruinosa, and M. gigantea) were screened to evaluate their total phenolic contents and activities as cholinesterase inhibitors, nitric oxide (NO) production inhibitors, tyrosinase inhibitors, and antioxidants. The bark of M. denticulata showed the highest total phenolic content (2682 mg gallic acid equivalent (GAE)/100 g) and free radical scavenging activity (IC50 = 0.063 mg/mL). All of the samples inhibited linoleic acid peroxidation by greater than 80%, with the leaves of M. gigantea exhibiting the highest inhibition of 92.21%. Most of the samples exhibited significant antioxidant potential. The bark of M. denticulata and the leaves of both M. pruinosa and M. gigantea exhibited greater than 50% tyrosinase inhibition, with the bark of M. denticulata having the highest percentage of inhibition (68.7%). The bark and leaves of M. denticulata exhibited greater than 50% inhibition (73.82% and 54.50%, resp.) of the acetylcholinesterase enzyme (AChE), while none of the samples showed any significant inhibition of butyrylcholinesterase (BChE). Only the bark of M. denticulata and M. gigantea displayed greater than 50% inhibition of nitric oxide production in cells (81.79% and 56.51%, resp.). These bioactivities indicate that some Macaranga spp. have therapeutic potential in medicinal research.
    Matched MeSH terms: Antioxidants/chemistry*
  8. Khaledi H, Alhadi AA, Yehye WA, Ali HM, Abdulla MA, Hassandarvish P
    Arch Pharm (Weinheim), 2011 Nov;344(11):703-9.
    PMID: 21953995 DOI: 10.1002/ardp.201000223
    A new series of gallic hydrazones containing an indole moiety was synthesized through the reaction of gallic hydrazide and different indole carboxaldehydes. Their antioxidant activities were determined on DPPH radical scavenging and inhibition of lipid peroxidation. The in-vitro cytotoxic activities of the compounds were evaluated against HCT-116 (human colon cancer cell line) and MCF-7 (estrogen-dependent human breast cancer cell line) by the MTT method. An attempt to correlate the biological results with their structural characteristics has been done. A limited positive structure activity relationship was found between cytotoxic and antioxidant activities.
    Matched MeSH terms: Antioxidants/chemistry
  9. Jeyaraj EJ, Lim YY, Choo WS
    Sci Rep, 2022 09 01;12(1):14890.
    PMID: 36050436 DOI: 10.1038/s41598-022-19146-z
    Clitoria ternatea flower is a traditional medicinal herb that has been used as a natural food colourant. As there are limited studies on investigating the bioactivities of the anthocyanin-rich fraction of Clitoria ternatea flower, this study aimed to determine an efficient column chromatography method to obtain the anthocyanin-rich fraction from this flower and characterise its composition, antioxidant, antibacterial, and cytotoxic activities. Amberlite XAD-16 column chromatography was more efficient in enriching the total anthocyanin content (TAC) of the fraction with the highest TAC to total phenolic content (TPC) ratio of 1:6 than that using C18-OPN. A total of 11 ternatin anthocyanins were characterised in the anthocyanin-rich fraction by LC-MS analysis. The antioxidant activity of the anthocyanin-rich fraction was more potent in the chemical-based assay with an IC50 value of 0.86 ± 0.07 mg/mL using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay than cellular antioxidant assay using RAW 264.7 macrophages. In vitro cytotoxicity assay using human embryonic kidney HEK-293 cell line showed the anthocyanin-rich fraction to be more toxic than the crude extracts. The anthocyanin-rich fraction had more potent antibacterial activity than the crude extracts against Bacillus cereus, Bacillus subtilis, and Escherichia coli. The anthocyanin-rich fraction of C. ternatea has the potential to be used and developed as a functional food ingredient or nutraceutical agent.
    Matched MeSH terms: Antioxidants/chemistry
  10. Hellal K, Maulidiani M, Ismail IS, Tan CP, Abas F
    Molecules, 2020 Mar 10;25(5).
    PMID: 32164186 DOI: 10.3390/molecules25051247
    Claims of effective therapy against diabetes using plants including Peganum harmala L., Zygophyllum album, Anacyclus valentinus L., Ammodaucus leucotrichus, Lupinus albus, and Marrubium vulgare in Algerian empirical medicine prompted our interest in evaluating their antidiabetic activity by screening their free radical scavenging (DPPH), α-glucosidase, and nitric oxide (NO) inhibitory activities as well as the total phenolic content (TPC). Extracts of the selected plants were prepared using different ratios of ethanol (0, 50, 80, and 100%). In this study, 100%, and 80% ethanol extracts of L. albus were found to be the most potent, in inhibiting α-glucosidase activity with IC50 values of 6.45 and 8.66 μg/mL, respectively. The 100% ethanol extract of A. leucotrichus exhibited the highest free radical scavenging activity with an IC50 value of 26.26 μg/mL. Moreover, the highest TPC of 612.84 μg GAE/mg extract was observed in M. vulgare, extracted with 80% ethanol. Metabolite profiling of the active extract was conducted using 1H-NMR metabolomics. Partial least square analysis (PLS) was used to assess the relationship between the α-glucosidase inhibitory activity of L. albus and the metabolites identified in the extract. Based on the PLS model, isoflavonoids (lupinoisoflavone G, lupisoflavone, lupinoisolone C), amino acids (asparagine and thiamine), and several fatty acids (stearic acid and oleic acid) were identified as metabolites that contributed to the inhibition of α-glucosidase activity. The results of this study have clearly strengthened the traditional claim of the antihyperglycemic effects of L. albus.
    Matched MeSH terms: Antioxidants/chemistry*
  11. Gao X, Santhanam RK, Xue Z, Jia Y, Wang Y, Lu Y, et al.
    J Food Sci, 2020 Apr;85(4):1060-1069.
    PMID: 32147838 DOI: 10.1111/1750-3841.15084
    Inonotus obliquus is a traditional mushroom well known for its therapeutic value. In this study, various solvent fractions of I. obliquus were preliminarily screened for their antioxidant, α-amylase and α-glucosidase inhibition properties. To improve the drug delivery, the active fraction (ethyl acetate fraction) of I. obliquus was synthesized into fungisome (ethyl acetate phophotidyl choline complex, EAPC) and its physical parameters were assessed using Fourier transform infrared spectroscopy (FTIR), High performance liquid chromatography (HPLC), Scanning electron microscope (SEM), and ς potential analysis. Then normal human hepatic L02 cells was used to evaluate the cytotoxicity of EAPC. The results showed that EA fraction possesses significant free radical scavenging, α-amylase and α-glucosidase inhibition properties. FTIR, SEM, and HPLC analysis confirmed the fungisome formation. The particle size of EAPC was 102.80 ± 0.42 nm and the ς potential was -54.30 ± 0.61 mV. The percentage of drug entrapment efficiency was 97.13% and the drug release rates of EAPC in simulated gastric fluid and simulated intestinal fluid were 75.04 ± 0.29% and 93.03 ± 0.36%, respectively. EAPC was nontoxic to L02 cells, however it could selectively fight against the H2 O2 induced oxidative damage in L02 cells. This is the first study to provide scientific information to utilize the active fraction of I. obliquus as fungisome. PRACTICAL APPLICATIONS: Inonotus obliquus (IO) is a traditional medicinal fungus. The extracts of IO have obvious antioxidant and hypoglycemic activities. Ethyl acetate (EA) fraction of IO was encapsulated in liposomes to form EAPC. EAPC has a sustained-release effect. It has nontoxic to L02 cells and could protect L02 cells from oxidative damage caused by hydrogen peroxide. This study could provide new ideas for the treatment of diabetes.
    Matched MeSH terms: Antioxidants/chemistry
  12. Lee SY, Mediani A, Ismail IS, Maulidiani, Abas F
    BMC Complement Altern Med, 2019 Jan 07;19(1):7.
    PMID: 30616569 DOI: 10.1186/s12906-018-2413-4
    BACKGROUND: Neptunia oleracea is a plant cultivated as vegetable in Southeast Asia. Previous works have revealed the potential of this plant as a source of natural antioxidants and α-glucosidase inhibitors. Continuing our interest on this plant, the present work is focused in identification of the bioactive compounds from different polarity fractions of N. oleracea, namely hexane (HF), chloroform (CF), ethyl acetate (EF) and methanol (MF).

    METHODS: The N. oleracea fractions were obtained using solid phase extraction (SPE). A metabolomics approach that coupled the use of proton nuclear magnetic resonance (1H NMR) with multivariate data analysis (MVDA) was applied to distinguish the metabolite variations among the N. oleracea fractions, as well as to assess the correlation between metabolite variation and the studied bioactivities (DPPH free radical scavenging and α-glucosidase inhibitory activities). The bioactive fractions were then subjected to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis to profile and identify the potential bioactive constituents.

    RESULTS: The principal component analysis (PCA) discriminated EF and MF from the other fractions with the higher distributions of phenolics. Partial least squares (PLS) analysis revealed a strong correlation between the phenolics and the studied bioactivities in the EF and the MF. The UHPLC-MS/MS profiling of EF and MF had tentatively identified the phenolics present. Together with some non-phenolic metabolites, a total of 37 metabolites were tentatively assigned.

    CONCLUSIONS: The findings of this work supported that N. oleracea is a rich source of phenolics that can be potential antioxidants and α-glucosidase inhibitors for the management of diabetes. To our knowledge, this study is the first report on the metabolite-bioactivity correlation and UHPLC-MS/MS analysis of N. oleracea fractions.

    Matched MeSH terms: Antioxidants/chemistry
  13. Razab R, Abdul-Aziz A
    Nat Prod Commun, 2010 Mar;5(3):441-5.
    PMID: 20420325
    Plants that contain high amounts of polyphenolic compounds are potential candidates for natural antioxidant sources. Studies are on going in the search for new sources of antioxidants. Not much data are available on the antioxidant capacity of tropical herbs. With this in mind, 19 commonly consumed Malaysian herbs were analyzed for their polyphenolic content and antioxidant activities. A majority of these plants have never been studied before with regards to their polyphenolic content and antioxidant activities. The shoots of Anacardium occidentale, the shoots and fruits of Barringtonia racemosa, Pithecellobium jiringa and Parkia speciosa had high polyphenolic contents (> 150 microg gallic acid equivalents/mg dried plant) and antioxidant activities when measured using the ferric reducing antioxidant power (FRAP) (>1.2 mM) and Trolox equivalent antioxidant capacity (TEAC) assays (>2.4 mM). A strong correlation was observed between the two antioxidant assays (FRAP vs TEAC) implying that the plants could both scavenge free radicals and reduce oxidants. There was also a strong correlation between the antioxidant activities and polyphenolic content suggesting the observed antioxidant activities were contributed mainly by the polyphenolics in the plants.
    Matched MeSH terms: Antioxidants/chemistry*
  14. Tan LT, Chan KG, Chan CK, Khan TM, Lee LH, Goh BH
    Biomed Res Int, 2018;2018:4823126.
    PMID: 29805975 DOI: 10.1155/2018/4823126
    Mangrove derived microorganisms constitute a rich bioresource for bioprospecting of bioactive natural products. This study explored the antioxidant potentials of Streptomyces bacteria derived from mangrove soil. Based on 16S rRNA phylogenetic analysis, strain MUM292 was identified as the genus Streptomyces. Strain MUM292 showed the highest 16S rRNA gene sequence similarity of 99.54% with S. griseoruber NBRC12873T. Furthermore, strain MUM292 was also characterized and showed phenotypic characteristics consistent with Streptomyces bacteria. Fermentation and extraction were performed to obtain the MUM292 extract containing the secondary metabolites of strain MUM292. The extract displayed promising antioxidant activities, including DPPH, ABTS, and superoxide radical scavenging and also metal-chelating activities. The process of lipid peroxidation in lipid-rich product was also retarded by MUM292 extract and resulted in reduced MDA production. The potential bioactive constituents of MUM292 extract were investigated using GC-MS and preliminary detection showed the presence of pyrazine, pyrrole, cyclic dipeptides, and phenolic compound in MUM292 extract. This work demonstrates that Streptomyces MUM292 can be a potential antioxidant resource for food and pharmaceutical industries.
    Matched MeSH terms: Antioxidants/chemistry
  15. Mohamad H, Lajis NH, Abas F, Ali AM, Sukari MA, Kikuzaki H, et al.
    J Nat Prod, 2005 Feb;68(2):285-8.
    PMID: 15730265
    Phytochemical studies on the rhizomes of Etlingera elatior have resulted in the isolation of 1,7-bis(4-hydroxyphenyl)-2,4,6-heptatrienone (1), demethoxycurcumin (2), 1,7-bis(4-hydroxyphenyl)-1,4,6-heptatrien-3-one (3), 16-hydroxylabda-8(17),11,13-trien-15,16-olide (4), stigmast-4-en-3-one, stigmast-4-ene-3,6-dione, stigmast-4-en-6beta-ol-3-one, and 5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol. Compounds 1 and 4 are new, and their structures were elucidated by analysis of spectroscopic data. Diarylheptanoids 1-3 were found to inhibit lipid peroxidation in a more potent manner than alpha-tocopherol.
    Matched MeSH terms: Antioxidants/chemistry
  16. Khoo HE, Azlan A, Ismail A, Abas F
    Molecules, 2012 Aug 14;17(8):9754-73.
    PMID: 22893021 DOI: 10.3390/molecules17089754
    Solid phase extraction (SPE) using Sep-Pak® cartridges is one of the techniques used for fractionation of antioxidant compounds in waste of dabai oil extraction (defatted dabai parts). The aim of this study was to determine the phenolic compounds and antioxidant capacity in crude extracts and several SPE fractions from methanolic extract of defatted dabai pulp and peel. Based on SPE, Sep-Pak® cyanopropyl and C₁₈ cartridges were used to fractionate the antioxidant-rich crude extracts into water and methanolic fractions. Analyzed using LC-MS, flavonoids, anthocyanins, saponin derivatives and other unknown antioxidative compounds were detected in the defatted dabai crude extracts and their SPE fractions. Anthocyanins were the major phenolic compounds identified in the defatted dabai peel and detected in most of the SPE fractions. Methanolic fractions of defatted dabai parts embraced higher total phenolics and antioxidant capacity than water fractions. This finding also revealed the crude extracts of defatted dabai peel have the most significant antioxidant properties compared to the methanolic and water fractions studied. The crude extract of defatted dabai parts remain as the most potent antioxidant as it contains mixture of flavonoids, anthocyanins and other potential antioxidants.
    Matched MeSH terms: Antioxidants/chemistry*
  17. Zahari A, Cheah FK, Mohamad J, Sulaiman SN, Litaudon M, Leong KH, et al.
    Planta Med, 2014 May;80(7):599-603.
    PMID: 24723007 DOI: 10.1055/s-0034-1368349
    The crude extract of the bark of Dehaasia longipedicellata exhibited antiplasmodial activity against the growth of Plasmodium falciparum K1 isolate (resistant strain). Phytochemical studies of the extract led to the isolation of six alkaloids: two morphinandienones, (+)-sebiferine (1) and (-)-milonine (2); two aporphines, (-)-boldine (3) and (-)-norboldine (4); one benzlyisoquinoline, (-)-reticuline (5); and one bisbenzylisoquinoline, (-)-O-O-dimethylgrisabine (6). Their structures were determined on the basis of 1D and 2D NMR, IR, UV, and LCMS spectroscopic techniques and upon comparison with literature values. Antiplasmodial activity was determined for all of the isolated compounds. They showed potent to moderate activity with IC50 values ranging from 0.031 to 30.40 µM. (-)-O-O-dimethylgrisabine (6) and (-)-milonine (2) were the two most potent compounds, with IC50 values of 0.031 and 0.097 µM, respectively, that were comparable to the standard, chloroquine (0.090 µM). The compounds were also assessed for their antioxidant activities with di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium (IC50 = 18.40-107.31 µg/mL), reducing power (27.40-87.40 %), and metal chelating (IC50 = 64.30 to 257.22 µg/mL) having good to low activity. (-)-O-O-dimethylgrisabine (6) exhibited a potent antioxidant activity of 44.3 % reducing power, while di(phenyl)-(2,4,6-trinitrophenyl)iminoazanium and metal chelating activities had IC50 values of 18.38 and 64.30 µg/mL, respectively. Thus it may be considered as a good reductant with the ability to chelate metal and prevent pro-oxidant activity. In addition to the antiplasmodial and antioxidant activities, the isolated compounds were also tested for their cytotoxicity against a few cancer and normal cell lines. (-)-Norboldine (4) exhibited potent cytotoxicity towards pancreatic cancer cell line BxPC-3 with an IC50 value of 27.060 ± 1.037 µM, and all alkaloids showed no toxicity towards the normal pancreatic cell line (hTERT-HPNE).
    Matched MeSH terms: Antioxidants/chemistry
  18. Mohd Ghazali MA, Al-Naqeb G, Krishnan Selvarajan K, Hazizul Hasan M, Adam A
    Biomed Res Int, 2014;2014:539607.
    PMID: 24955361 DOI: 10.1155/2014/539607
    Polygonum minus (Polygonaceae) is a medicinal herb distributed throughout eastern Asia. The present study investigated antiproliferative effect of P. minus and its possible mechanisms. Four extracts (petroleum ether, methanol, ethyl acetate, and water) were prepared by cold maceration. Extracts were subjected to phytochemical screening, antioxidant, and antiproliferative assays; the most bioactive was fractionated using vacuum liquid chromatography into seven fractions (F1-F7). Antioxidant activity was measured via total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) assays. Antiproliferative activity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Most active fraction was tested for apoptosis induction and cell cycle arrest in HepG2 cells using flow cytometry and confocal microscopy. Apoptotic-related gene expression was studied by RT-PCR. Ethyl acetate extract was bioactive in initial assays. Its fraction, F7, exhibited highest antioxidant capacity (TPC; 113.16 ± 6.2 mg GAE/g extract, DPPH; EC50: 30.5 ± 3.2 μg/mL, FRAP; 1169 ± 20.3 μmol Fe (II)/mg extract) and selective antiproliferative effect (IC50: 25.75 ± 1.5 μg/mL). F7 induced apoptosis in concentration- and time-dependent manner and caused cell cycle arrest at S-phase. Upregulation of proapoptotic genes (Bax, p53, and caspase-3) and downregulation of antiapoptotic gene, Bcl-2, were observed. In conclusion, F7 was antiproliferative to HepG2 cells by inducing apoptosis, cell cycle arrest, and via antioxidative effects.
    Matched MeSH terms: Antioxidants/chemistry
  19. Zakaria ZA, Kamisan FH, Mohd Nasir N, Teh LK, Salleh MZ
    Nutrients, 2019 Dec 04;11(12).
    PMID: 31817058 DOI: 10.3390/nu11122945
    This study aimed to determine the antioxidant and hepatoprotective activities of semi-purified aqueous partition obtained from the methanol extract of Dicranopteris linearis (AQDL) leaves against paracetamol (PCM)-induced liver intoxication in rats. The test solutions, AQDL (50, 250, and 500 mg/kg), were administered orally to rats (n = 6) once daily for seven consecutive days followed by the hepatotoxicity induction using 3 g/kg PCM (p.o.). Blood was collected for serum biochemical parameters analysis while the liver was collected for histopathological examination and endogenous antioxidant enzymes analysis. AQDL was also subjected to antioxidant determination and phytochemical analysis. Results obtained show that AQDL possessed high total phenolic content (TPC) value and remarkable radical scavenging activities. AQDL also significantly (p < 0.05) reduced the liver weight/body weight (LW/BW) ratio or serum level of ALT, AST, and total bilirubin while significantly (p < 0.05) increase the level of superoxide dismutase (SOD) and catalase (CAT) without affecting the malondialdehyde (MDA) in the liver indicating its hepatoprotective effect. Phytoconstituents analyses showed only the presence of saponins and triterpenes, but lack of flavonoids. In conclusion, AQDL exerts hepatoprotective activity via its high antioxidant potential and ability to modulate the endogenous enzymatic antioxidant defense system possibly via the synergistic action of saponins and triterpenes.
    Matched MeSH terms: Antioxidants/chemistry
  20. Agatonovic-Kustrin S, Morton DW, Ristivojević P
    J Chromatogr A, 2016 Oct 14;1468:228-235.
    PMID: 27670751 DOI: 10.1016/j.chroma.2016.09.041
    The aim of this study was to develop and validate a rapid and simple high performance thin layer chromatographic (HPTLC) method to screen for antioxidant activity in algal samples. 16 algal species were collected from local Victorian beaches. Fucoxanthin, one of the most abundant marine carotenoids was quantified directly from the HPTLC plates before derivatization, while derivatization either with 2,2-diphenyl-1-picrylhydrazyl (DPPH) or ferric chloride (FeCl3) was used to analyze antioxidants in marine algae, based on their ability to scavenge non biological stable free radical (DPPH) or to chelate iron ions. Principal component analysis of obtained HPTLC fingerprints has classified algae species into 5 groups according to their chemical/antioxidant profiles. The investigated brown algae samples were found to be rich in non-and moderate-polar compounds and phenolic compounds with antioxidant activity. Most of the phenolic iron chelators also have shown free radical scavenging activity. Strong positive and significant correlations between total phenolic content and DPPH radical scavenging activity showed that, phenolic compounds, including flavonoids are the main contributors of antioxidant activity in these species. The results suggest that certain brown algae possess significantly higher antioxidant potential when compared to red or green algae and could be considered for future applications in medicine, dietary supplements, cosmetics or food industries. Cystophora monilifera extract was found to have the highest antioxidant concentration, followed by Zonaria angustata, Cystophora pectinate, Codium fragile, and Cystophora pectinata. Fucoxanthin was found mainly in the brown algae species. The proposed methods provide an edge in terms of screening for antioxidants and quantification of antioxidant constituents in complex mixtures. The current application also demonstrates flexibility and versatility of a standard HPTLC system in the drug discovery. Proposed methods could be used for the bioassay-guided isolation of unknown natural antioxidants and subsequent identification if combined with spectroscopic identification.
    Matched MeSH terms: Antioxidants/chemistry*
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links